Weed seed destruction device with a straw guide surface

Abstract

A combine harvester includes a straw discharge rotor discharging into a straw stream and a sieve discharging into a chaff stream and a weed seed destructor section receiving the chaff and weed seeds for devitalizing at least some weed seeds. The straw is maintained out of the chaff stream by a guide construction having a front curved section underneath the rotor and a rear section which comprises a row of cantilevered flexible fingers which flex to assist in flow of the straw thereover and release of the straw from the rear end thereof. The rear ends of the fingers are thus unconnected and allow the straw to be freely released onto a dividing wall extending to the entrance to a straw chopper. The row of fingers can be carried on a support bar which is reciprocated around a transverse axis by a connection to a reciprocating element of the combine.

1 . A combine harvester comprising:
 a separation system for separating from harvested crop a first material at a first discharge location comprising straw and a second material comprising chaff and weed seeds at a second discharge location;   a first material discharge section at the first discharge location arranged to move the separated first material rearward for discharge along a straw discharge path, the first material discharge section including a rotary body and a guide surface cooperating with the rotary body;   the separation system including at least one sieve arranged at a height below the first material discharge section, the sieve having openings thereon allowing passage of separation air to separate chaff and weed seeds from grain and the sieve having a rear edge over which the chaff and weed seeds are discharged;   a weed seed destructor section for receiving the second material comprising chaff and weed seeds, the weed seed destructor section including components therein for devitalizing at least some weed seeds in the second material;   and a guide construction for guiding the first material comprising straw from the discharge section in the straw discharge path while maintaining separation of the first material from the second material and thus acting to reduce passage of the first material to the weed seed destructor section;   the guide construction dividing a surface over which the first material passes;   the guide construction having openings therethrough for passage of the separation air from the sieve into the straw discharge path;   the guide construction being arranged to allow the first material to be released from a rear end thereof to continue along the straw discharge path.   
     
     
         2 . The combine harvester according to  claim 1  wherein the guide construction comprises at least one flexible element which flexes during operation to assist in flow of the first material thereover and release of the first material from the rear end thereof. 
     
     
         3 . The combine harvester according to  claim 1  wherein the guide construction comprises a plurality of fingers extending rearwardly from the front section and transversely spaced apart to allow passage of the separation air therebetween. 
     
     
         4 . The combine harvester according to  claim 3  wherein the fingers are round in cross section. 
     
     
         5 . The combine harvester according to  claim 3  wherein the fingers are spaced wider apart than the width of the fingers so as to create little restriction to air flow to avoid change in the sieve cleaning efficiency. 
     
     
         6 . The combine harvester according to  claim 1  wherein the guide construction comprises an array of elements cantilevered rearwardly from a support at or on the front section such that the first material sheds rearwardly freely from the cantilevered elements. 
     
     
         7 . The combine harvester according to  claim 6  wherein the elements are unsupported and unconnected at a rear end thereof so as not to impede free flow of the first material from the rear end. 
     
     
         8 . The combine harvester according to  claim 6  wherein the elements do not allow any hair-pinning of material as the rear end of the elements and are unobstructed to promote the first material to slide off without restriction. 
     
     
         9 . The combine harvester according to  claim 6  wherein the array of elements spans across a full width of the straw discharge passage. 
     
     
         10 . The combine harvester according to  claim 1  wherein the rear edge of the guide construction terminates adjacent an impervious divider panel separating the straw discharge path from the weed seed destructor section. 
     
     
         11 . The combine harvester according to  claim 1  wherein the rotor comprises a beater or internal chopper and the guide surface is curved to as to partly wrap around the beater or chopper. 
     
     
         12 . The combine harvester according to  claim 11  wherein the rotor is arranged to form the first material into a stream and the guide surface extends to a rear edge from which the stream is released. 
     
     
         13 . The combine harvester according to  claim 1  wherein the guide construction is inclined downwardly and rearwardly from the rear edge of the guide surface to allow flow of the first material rearwardly from the rear edge over an entrance of the weed seed destructor section. 
     
     
         14 . The combine harvester according to  claim 1  wherein the guide construction is flexible to provide flexing or whipping or bending movements of the rear end of the components of the guide construction to assist in release of the first material from the rear end thereof. 
     
     
         15 . The combine harvester according to  claim 14  wherein the components of the guide construction are flexible allowing a whipping action, up and down as well as side to side to quickly move any lodged straw that could build up in wet conditions. 
     
     
         16 . The combine harvester according to  claim 1  wherein there is provided a straw spreading section arranged to receive the first material from the first material discharge section and to spread the first material at least to the sides of the combine harvester. 
     
     
         17 . The combine harvester according to  claim 16  wherein the straw spreading section includes a rotating straw chopper cooperating with stationary cutting blades. 
     
     
         18 . The combine harvester according to  claim 1  wherein the guide construction is mounted for reciprocating movement of a rear end thereof. 
     
     
         19 . The combine harvester according to  claim 18  wherein the guide construction is mounted at a front support which is pivotal about a transverse axis for upward and downward reciprocating movement of a rear end of the guide wall. 
     
     
         20 . The combine harvester according to  claim 18  wherein the upward and downward reciprocating movement of the rear end thereof is driven by a link from a reciprocating movement of a component of the combine harvester.